I'd like to be able to compose xml documents.

With the old dtd stuff this was done with entities,
e.g. see the build scripts. :-)

When using xsd, the only option is XInclude.
But this isn't supported until java5

http://java.sun.com/j2se/1.5.0/docs/api/javax/xml/parsers/SAXParserFactory.html#setXIncludeAware(boolean)

Can we add some reflection processing to the static initializer in
SaxJBossXBParser that tries to set this to true if the method exists.

It should also be possible to make this work by setting
features before Java5?